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5 Answers

Using 1" XPS as the vent baffle

I am thinking of using 1" XPS as a vent baffle in a cathedral ceiling, similar to what is shown here:

I wouldn't actual use that product, but the same idea. I am thinking of spacing the xps 1.5" off of the underside of the roof sheathing, and sealing any gaps with a combination of sprayfoam and tape. The roof would have soffit and ridge vents. The rest of the bay (approx 7") would be insulated with fiberglass bats. I am building in a cold climate, and the space is a conditioned room over an unconditioned garage. The roof is 2x10 stick framed.

In Energy efficiency and durability | Asked By Tobias Richon | Feb 27 09
2 Answers

Insulation achieves its maximum R-value by touching the air barrier on all it surfaces. How much R-value does attic insulation

loose by being open at the top?

In General questions | Asked By terry nordbye | Mar 15 09
10 Answers

any advice about insulating walls in an old house?

i'd like to not have to tear out the interior walls. foam products inserted from the top might expand too fast and not make it to the floor. someone suggested pouring in vermiculite between the studs. i'd really appreciate suggestions/advice. thanks, robin [email protected]

In Green building techniques | Asked By robin kautz | Feb 5 09
2 Answers

Make-up air for Kitchen Range Hoods

I have a builder that insists on installing a 1200 cfm range hood. What is recommended for make-up air (rate and preferred installation)

In Mechanicals | Asked By Sean Bleything | Mar 2 09
2 Answers

How much R- value do insulating shades/ blinds add to a window?

They are somewhat tight on the top and bottom but have around a half to quarter inch space up the sides. Installers and salesman will tell you they can make hair grow on an apple- should I believe them?

In Green products and materials | Asked By terry nordbye | Feb 28 09
2 Answers

Does it make sense to use ICFs for a frost protected shallow foundation?

I will be building a house near Amherst Ma. in an area with a high water table. FPSF seems like the way to go. ICFs are quick and easy. Is there any reason not to use them for this? Any opinions on insulation - xps or eps? Any recommendations on waterproof material under the slab? I have heard polyethylene gets brittle and breaks down over time.

In Energy efficiency and durability | Asked By Ralph Hill | Mar 11 09
2 Answers

Do I need house wrap under exterior wall rigid foam ?


Do I need to put house wrap ( Tyvek etc) between exterior 3/4 "iso rigid foam (taped)? Can I go naked or just 15 lb felt?

I'm looking at tech drawings on the site and it's not shown.

My guess is not, but why not ask before I go through all this an d do something dumb.


In Green building techniques | Asked By Steve Greenberg | Mar 10 09
3 Answers

High-performance insulation in cathedral ceiling

I'd love to hear feedback on the most efficient and cost-effective way to insulate a cathedral ceiling constructed with scissor trusses (residential construction). I'm considering having the trusses built with 16" or 20" heels and blowing in cellulose to achieve the insulation levels desired. Another option could be spray-foam (closed cell). I'd love any feedback, i.e., pros/cons to each or a better method.

In Green building techniques | Asked By Claire Anderson | Feb 3 09
1 Answer

How green are IKEA products?

A lot people, particularly college-age people, trek to IKEA when it comes to interior design. Given that IKEA promotes itself as a "green" company, what is your take on the products they sell? How green are IKEA products?

In Green products and materials | Asked By Brian Becker | Mar 3 09
2 Answers

cantilever steps

I want to move my steps- inside. I want to have cantilever steps, but can't find any places that make them. As this is residential, it seems to make it even harder to find someone.
Also, I have 6 inch solid concrete exterior walls- will it be safe to attach cantilevers to the wall- I wouldn't think I would use more than a 2-3 inch 'bolt' or other attachment to the wall- would it disrupt the integrity of the wall. I live in an earthberm home and that wall is covered with dirt.

In General questions | Asked By Deb Cirner | Feb 11 09
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